JP2011135521A - Optical communication apparatus, communication harness and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: an optical communication apparatus capable of achieving coexistence of control area network (CAN) based communication and optical communication; a communication harness; and a communication system. <P>SOLUTION: An optical communication apparatus includes, on a substrate 10: connecting sections 11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h connected to a plurality of unshielded twisted pair (UTP) cables; signal lines 12 and 13 connecting the connecting sections; a CAN transmitting/receiving section 14, connected to the signal lines 12 and 13, for transmitting/receiving an electrical signal based on a CAN; and a converting section 15 for converting a signal received by the CAN transmitting/receiving section 14 into an optical signal, transmitting the optical signal from an optical connector to an optical communication line 3, converting the optical signal received by the optical connector via the optical communication line 3 into an electrical signal and outputting the electrical signal to the CAN transmitting/receiving section 14 so as to transmit it from the CAN transmitting/receiving section 14. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a communication system capable of suppressing ringing in a communication line by connecting between communication apparatuses that perform electrical communication and once converting them into an optical signal, thereby improving communication quality between the communication apparatuses. The present invention relates to an optical communication apparatus, a communication harness, and a communication system capable of realizing a mixture of electrical communication and optical communication based on the above protocol.

  In recent years, systems that connect a plurality of communication devices, assign functions to the communication devices, exchange data with each other, and perform various processes in cooperation have been used in various fields. For example, in the field of an in-vehicle LAN (Local Area Network) arranged in a vehicle, an ECU (Electronic Control Unit) has a communication function, and each ECU performs a process specialized for each other. Various functions are realized as a system by exchanging data.

  While the functions of each ECU are specialized, the number of devices (nodes) provided with communication means is increasing because the functions that should be enabled in the entire communication system tend to increase. However, when many nodes are connected to the communication line, ringing or the like is likely to occur, and there is a problem that the frequency of occurrence of communication failures increases. In communication using the current CAN (Controller Area Network), there is a limit on the number of nodes that can be connected to a communication line.

  As the function of the entire communication system increases and the number of devices increases, the influence of electromagnetic noise on the communication line and other signal lines cannot be ignored. In particular, in the field of vehicles, high voltage cables are arranged in vehicles due to the spread of EV (Electric Vehicle) and HEV (Hybrid EV). In order to eliminate the influence of electromagnetic noise, it is desirable to use a shielded (STP: Shielded Twisted Pair) communication line. However, conventionally used ECUs are configured to transmit and receive signals via UTP, and it is not practical to change all connectors and the like to be compatible with STP.

  In order to prevent ringing, the communication line is divided into a plurality of parts, ECUs are connected to different communication lines, and the number of nodes connected to one communication line is limited. In these configurations, different communication lines are connected by a gateway (GW) that controls transmission and reception of data. However, in the configuration in which the GW is included in the communication system in order to limit the number of nodes per communication line, the number of parts in the entire communication system increases and the cost of the entire system increases.

  Therefore, it is conceivable to employ optical communication using an optical device that is not affected by electromagnetic noise. In the field of vehicles, a configuration in which a part is realized by optical communication has been proposed (Patent Document 1).

JP 2008-219353 A

  However, as described above, CAN is widely adopted in communication between conventional ECUs. Even when a part is realized by optical communication, it is desirable that each ECU can use a communication function based on CAN as it is. This is because if a CAN communication function can be used, a system can be constructed by connecting a conventional ECU.

  In particular, in the CAN protocol, each node constantly monitors a communication line in order to perform arbitration processing for communication collision. Even when each node transmits itself, the transmission process is continued when the signal transmitted through the communication line matches the signal transmitted by itself, and the transmission process is stopped when they do not match. Even when a part is optical communication, it is necessary to configure between optical communication and electrical communication so that each node can detect both signals transmitted by itself and signals from others.

  The present invention has been made in view of such circumstances, and an optical communication device capable of realizing a mixture of electrical communication based on a predetermined protocol and optical communication, and a communication harness including the optical communication device And it aims at providing the communication system containing the said optical communication apparatus.

  An optical communication apparatus according to a first aspect of the present invention includes a plurality of connection portions connected to each of a plurality of communication lines, one optical connection portion connected to the optical communication line, and a signal line that connects each connection portion in a bus shape. And a transmission / reception unit connected to the signal line and transmitting / receiving a signal via the signal line based on a predetermined protocol, connected to the optical connection unit and the transmission / reception unit, and received by the transmission / reception unit A conversion unit that converts a signal into an optical signal, outputs the optical signal to the optical connection unit, converts an optical signal received through the optical connection unit into an electrical signal, and outputs the electrical signal to the transmission / reception unit; To do.

  The optical communication apparatus according to the second invention is characterized in that the predetermined protocol is CAN (Control Area Network).

  An optical communication apparatus according to a third aspect of the invention is characterized in that the connection unit, the transceiver, the optical connection unit, and the conversion unit are mounted on a substrate, and the signal line is printed on the substrate.

  An optical communication apparatus according to a fourth aspect of the present invention further includes a circuit connected to the signal line and shaping a waveform of a signal output to the signal line.

  A communication harness according to a fifth invention is the optical communication device according to any one of the first to fourth inventions, a plurality of communication lines respectively connected to the plurality of connection portions of the optical communication device, and the optical communication. And an optical communication line connected to the optical connection portion of the apparatus.

  A communication system according to a sixth aspect of the invention includes a plurality of communication lines to which a plurality of communication devices are respectively connected, and the optical communication device according to any one of the first to fourth inventions to which the plurality of communication lines are connected. It is characterized by including.

  In the present invention, a transmission / reception unit that transmits and receives a signal based on a predetermined protocol (for example, CAN) that needs to be monitored including a signal transmitted to a communication line, particularly a signal transmitted by itself (arbitration processing if CAN). (Arbitration)) is connected to a plurality of connection portions to which a plurality of telecommunication lines are connected in a bus shape. Accordingly, signals that can be transmitted as a result of the arbitration process by the communication devices (nodes) connected to the ends of the plurality of connection units are transmitted to the signal lines. The signal is received by the transmission / reception unit, output to the conversion unit, converted into an optical signal, and transmitted to the optical communication line via the optical connection unit. As a result, other communication devices connected via the optical communication line can monitor signals from other communication devices that perform electrical communication connected via a plurality of connection units. In addition, the transmission / reception unit transmits the optical signal to the signal line based on a predetermined protocol while the optical connection unit receives the optical signal via the optical communication line and attempts to transmit the signal converted by the conversion unit to the signal line. The output signal is continuously output to the conversion unit. As a result, other communication devices connected via the optical communication line can always monitor the signals that are actually transmitted, and communication is possible after performing the arbitration process.

  In the present invention, each component is mounted on a substrate, and signal lines are printed on the substrate. A communication line connected to a communication device (node) that performs electrical communication based on CAN is connected to each connection unit, and the optical connection unit of the same optical communication device is connected to the optical connection unit via the optical communication line. With this simple configuration, it is possible to actually construct a communication system based on CAN in which optical communication is mixed.

  In the present invention, since a circuit for shaping the signal waveform in the signal line is further provided, it is possible to more effectively suppress the influence of ringing by removing electromagnetic noise in electrical communication.

  In the case of the present invention, an electrical communication line is connected to the optical communication device of the present invention, a communication device (node) corresponding to CAN is connected to the communication line, an optical communication line is connected to the optical connection unit, With a configuration in which the optical communication device of the present invention is further connected to the optical communication line, a communication system in which CAN-based communication and optical communication are mixed can be easily constructed. Thereby, the communication based on the conventional CAN protocol can be maintained while suppressing the influence of electromagnetic noise and ringing.

It is an upper perspective view which shows the structure of the optical communication apparatus in this Embodiment. It is a block diagram which shows the structure of the communication system containing an optical communication apparatus.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.

  FIG. 1 is an upper perspective view showing the configuration of the optical communication apparatus 1 in the present embodiment. The optical communication apparatus 1 includes connection portions 11b, 11c, 11d, and 11e that are metal connectors including a connection portion 11a to which a connector portion 21a of a CAN-compatible UTP (Unshielded Twisted Pair) cable 2a is connected on a substrate 10. , 11f, 11g, and 11h are mounted. On the substrate 10, signal lines 12 and signal lines 13 for connecting the connection portions 11a, 11b, 11c, 11d, 11e, 11f, 11g, and 11h are printed. The signal line 12 and the signal line 13 on the substrate 10 are respectively connected to a CAN transmitting / receiving unit 14 mounted on the substrate 10. The CAN transmission / reception unit 14 is further connected to a conversion unit 15 mounted on the substrate 10, and the conversion unit 15 includes an optical connector (optical connection unit) and is connected to the connector unit 31 of the optical communication line 3. A shaping circuit 16 mounted on the substrate 10 is further connected to the signal lines 12 and 13.

  Each of the connecting portions 11a, 11b, 11c, 11d, 11e, 11f, 11g, and 11h has a female receptacle into which the connector portion 21a of the UTP cable 2a is fitted. Four connection portions 11 a, 11 b, 11 c, 11 d, 11 e, 11 f, 11 g, and 11 h are arranged in parallel at the peripheral portion of the substrate 10 so that all the receiving ports face the outside of the substrate 10. Even when the casing is put on the upper surface of the substrate 10, the receiving port is configured to be exposed. The connecting portion 11a has end portions of the signal lines 12 and 13 in the receptacle so that the signal lines 12 and 13 and the signal lines inside the UTP cable 21a are connected when the connector portion 21a is inserted.

  The signal line 12 and the signal line 13 are printed at the center of the substrate 10 so as to pass between the connection portions 11a, 11b, 11c, and 11d and the connection portions 11e, 11f, 11g, and 11h, respectively. The signal line 12 corresponds to CAN_H in CAN, and the signal line 13 corresponds to CAN_L. Signal lines are printed from the connection portions 11a, 11b, 11c, 11d, 11e, 11f, 11g, and 11h so as to be connected to the signal lines 12 and 13 in a bus form.

  The CAN transmitting / receiving unit 14 is connected to each of the signal line 12 and the signal line 13 and detects a signal based on a potential difference between the signal line 12 and the signal line 13 based on the CAN protocol. The CAN transmission / reception unit 14 has a transmission terminal (Tx) and a reception terminal (Rx), which are connected to the conversion unit 15. The CAN transmitting / receiving unit 14 converts the differential signal detected via the signal line 12 and the signal line 13 into a digital signal (0: dominant / 1: recessive) and outputs the digital signal from the reception terminal to the conversion unit 15. The CAN transmission / reception unit 14 inputs a digital signal output from the conversion unit 15 to be transmitted from a transmission terminal, converts the digital signal into a differential signal, and outputs the differential signal to the signal line 12 and the signal line 13.

  The conversion unit 15 includes a light emitting element such as a photodiode and a light receiving element such as an LED (Light Emitting Diode). The conversion unit 15 has a female-type receiving port into which the connector unit 31 of the optical communication line 3 is fitted, and is arranged on the peripheral portion of the substrate so that the receiving port faces the outside of the substrate 10. Even when the casing is put on the upper surface of the substrate 10, the receiving port is configured to be exposed.

  The conversion unit 15 outputs an optical signal from the light emitting element based on a signal output from the reception terminal of the CAN transmission / reception unit 14 and transmits the optical signal from the optical connector to the optical communication line 3. The optical signal associates digital data with / without light. That is, 0: dominant / 1: recessive corresponds to the presence / absence of light. The converter 15 receives the optical signal received from the optical communication line 3 via the optical connector by the light receiving element, converts it into an electrical signal, and outputs it from the CAN transceiver 14 to the transmission terminal for transmission.

  The shaping circuit 16 uses, for example, a band-pass filter and is configured to pass only signals having a predetermined ringing frequency and noise frequency, and removes ringing or noise in the signal lines 12 and 13.

  With the optical communication device 1 configured as described above, an optical signal from another communication device connected to the optical connector of the conversion unit 15 can be transmitted to another node according to the arbitration process of the CAN protocol. A signal transmitted by another communication device connected via the optical fiber 3 is transmitted to a node based on each CAN via the signal line 12 and the signal line 13, and other communication of the transmission source from the CAN transmission / reception unit 14. It is transmitted to the optical communication to the device. The other communication device can always monitor a signal that is actually transmitted, and can perform communication after performing arbitration processing based on CAN.

  FIG. 2 is a block diagram illustrating a configuration of a communication system including the optical communication device 1. The communication system is applied to, for example, an in-vehicle communication system that connects various control devices arranged in a vehicle and transmits / receives data based on CAN. The communication system shown in the block diagram of FIG. 2 includes two optical communication devices 1, an optical communication line 3 connected to the two optical communication devices 1, and two optical communication devices 1 via the optical communication line 3. The optical coupler 30 to be connected and the CAN nodes 4, 4,... Connected to the two optical communication devices 1 are included.

  The optical coupler 30 has a configuration in which two optical input units are provided on one side and two optical output units are provided on the other side. The optical coupler 30 is an optical distributor that distributes light input from the optical input unit into two and outputs the light to two optical output units. The first optical input unit of the optical coupler 30 is connected to the optical connector of the conversion unit 15 of one optical communication device 1 via the optical communication line 3, and the second optical input unit is the conversion of the other optical communication device 1. The optical connector of the unit 15 is connected via the optical communication line 3. The first optical output unit of the optical coupler 30 is connected to the conversion unit 15 of one optical communication device 1 via the optical communication line 3, and the second optical output unit is the conversion unit 15 of the other optical communication device 1. Are connected to each other via an optical communication line 3.

  As a result, the optical signal transmitted from the optical communication line 3 by the conversion unit 15 of one optical communication device 1 converting the signal input from the reception terminal of the CAN transmission / reception unit 14 is transmitted to the optical input unit of the optical coupler 30. Entered. The light is distributed by the optical coupler 30 and output from the two optical output units, and is received by both of the two optical communication apparatuses 1 and 1. Similarly, the optical signal transmitted by the other optical communication device 1 is distributed by the optical coupler 30 and received by both of the two optical communication devices 1 and 1. When the two optical communication devices 1 and 1 both transmit optical signals, the two optical signals are combined and distributed by the optical coupler 30, and the combined optical signals are respectively transmitted from the two optical output units. It is output and received by both of the two optical communication apparatuses 1 and 1.

  Each of the CAN nodes 4, 4,... Is an ECU that controls the operation of various devices (sensors, actuators, etc.) disposed in the vehicle, and has a microcomputer (Microcomputer) incorporating a CAN controller corresponding to the CAN. Operates by executing a control program.

  For example, when one CAN node 4 acquires information from a sensor (not shown), the CAN node 4 transmits the information so that other CAN nodes 4, 4,. When other CAN nodes 4, 4,... And the CAN transmission / reception unit 14 of the optical communication apparatus 1 are not transmitting signals through the UTP cable, the CAN nodes can transmit information. Information transmitted via the UTP cable is received by the optical communication device 1 and can be received by the other CAN nodes 4, 4,... Via the signal line 12 and the signal line 13, and also received by the CAN transceiver 14. To do. Therefore, the signal is output from the CAN transmitter / receiver 14 to the converter 15, converted into an optical signal, and received by the other optical communication device 1 via the optical coupler 30. In the other optical communication apparatus 1, the optical signal received by the conversion unit 15 is converted into an electrical signal and output to the CAN transmission / reception unit 14. The CAN transmission / reception unit 14 transmits if the transmission right is obtained by the arbitration processing in the signal line 12 and the signal line 13 based on CAN. Thereby, the information transmitted from the CAN node 4 on the one optical communication apparatus 1 side can be received by the CAN node 4 on the other optical communication apparatus 1 side through the optical communication.

  Thus, the CAN nodes 4, 4,... Remain in the function of the existing CAN controller, and the signals transmitted by themselves and the signals transmitted to the UTP cable are transmitted regardless of the communication via the optical coupler 30. It is possible to realize transmission / reception of data based on the CAN protocol by determining whether or not the transmission right is obtained based on whether they match or not, and performing arbitration processing based on CAN.

  The optical communication line 3 that connects the conversion unit 15 of one optical communication device 1 and the optical input unit of the optical coupler 30 and the conversion unit 15 of the other optical communication device 1 and the optical input unit of the optical coupler 30 are connected. It is preferable that the optical communication line 3 has substantially the same length. This is to suppress a difference in the timing at which the optical signal transmitted from one optical communication device 1 and the optical signal transmitted from the other optical communication device 1 are input to the optical coupler 30. . Thereby, the arbitration process is correctly performed. However, there may be some difference in the lengths of the optical communication lines 3 and 3 depending on the communication speed of the optical communication.

  An optical communication line 3 is connected to the optical communication apparatus 1, and another optical communication apparatus 1 to which another optical communication line 3 is connected is connected via an optical coupler 30, and eight connections of the optical communication apparatuses 1 and 1 are made. The communication harness which connected the UTP cable to the part 11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h is comprised. If a node having a CAN controller function conventionally used is connected to each UTP cable to the communication harness, a communication system in which CAN-based communication and optical communication are mixed can be easily constructed without a GW. it can. Thereby, communication based on the conventional CAN protocol can be realized while suppressing the influence of electromagnetic noise and ringing.

  In the present embodiment, the optical communication device 1 is configured to have eight connecting portions 11a, 11b, 11c, 11d, 11e, 11f, 11g, and 11h. However, the number of connection portions is not limited to eight, and any number of connection portions may be provided depending on the design.

  In the present embodiment, an example of a communication system including two optical communication devices 1 has been described. However, it is natural that a communication system including three or more optical communication apparatuses 1 can be realized. In this case, the optical coupler 30 to which the optical communication lines 3, 3,... Are connected is not two inputs and two outputs, but three or more, for example, optical signals from eight input portions are distributed to have eight output portions. It may be used.

  When the communication system according to the present embodiment is mounted on a vehicle, a plurality of CAN nodes 4, 4, 4 are connected to one optical communication device 1 according to a physical distance between the CAN nodes 4, 4,. In consideration of being able to connect ..., UTP cables and optical communication lines 3, 3, ... are appropriately arranged. Thereby, accurate communication can be performed without being affected by ringing, disturbance noise, or the like in the UTP cable.

  In the present embodiment, a system capable of mixing electrical communication and optical communication based on CAN has been described. However, the present invention is not limited to CAN, and can be applied to communications based on a protocol that constantly monitors and detects a collision including a signal transmitted to a communication line, particularly a signal transmitted by itself.

  The disclosed embodiments should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Optical communication apparatus 10 Board | substrate 11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h Connection part 12, 13 Signal line 14 CAN transmission / reception part 15 Conversion part 2a UTP cable (communication line)
3 Optical communication line 30 Optical coupler 4 CAN node (communication device)

Claims (6)

A plurality of connecting portions connected to each of a plurality of communication lines;
One optical connection connected to the optical communication line;
A signal line for connecting each connection portion in a bus shape;
A transmission / reception unit connected to the signal line and transmitting / receiving a signal via the signal line based on a predetermined protocol;
Connected to the optical connection unit and the transmission / reception unit, converts a signal received by the transmission / reception unit into an optical signal, outputs the optical signal to the optical connection unit, and electrically receives the optical signal received through the optical connection unit An optical communication apparatus comprising: a conversion unit that converts the signal into a signal and outputs the signal to the transmission / reception unit. The optical communication apparatus according to claim 1, wherein the predetermined protocol is CAN (Control Area Network). The connection unit, the transceiver, the optical connection unit, and the conversion unit are mounted on a substrate,
The optical communication apparatus according to claim 1, wherein the signal line is printed on the substrate. The optical communication apparatus according to claim 1, further comprising a circuit that is connected to the signal line and shapes a waveform of a signal output to the signal line. 5. The optical communication device according to claim 1, a plurality of communication lines respectively connected to the plurality of connection portions of the optical communication device, and the optical connection portion of the optical communication device. A communication harness comprising a single optical communication line. A communication system comprising: a plurality of communication lines to which a plurality of communication devices are respectively connected; and the optical communication device according to claim 1 to which the plurality of communication lines are connected.

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